Issues such as noise and power consumption need to be addressed in many electrical engineering applications, such as mixer circuits, charge pump circuits, pipeline converters, and comparator circuits.
For example, a sampling mixer circuit requires a quality amplifier, and designing a quality amplifier can be challenging, as circuit designers have to address issues such as sampling noise and power consumption. It is desirable to employ an amplifier in a sampling mixer circuit which dissipates as little power as possible.
A charge pump circuit typically requires a large quantity of switches in order to maintain and boost voltage levels to the desired value. It is desirable to be able to change the capacitance of a circuit element by changing the source (or drain) voltage of the circuit, rather than by activating large quantities of switches. This may prevent the need to generate complex clocking waveforms.
Pipeline converters generally require op amps, sampling capacitors, and capacitors in feedback in order to control the gain. The bandwith of op amps is approximately 10 times the frequency of operation, and therefore, the pipeline converters of the prior art generally consume a great deal of power. Avoiding the use of an op amp is thus desired, but a suitable substitute should be used in its place, especially a substitute having the advantages of higher speed and lower power consumption.
A comparator is a circuit element that compares two incoming signals and gives a digital output indicating which is larger. Comparator circuits typically require preamps before the latch because their use reduces the input referred offset by the amount of the gain of the preamp. The preamps dissipate static power and result in larger power consumption. In order to reduce power consumption, elimination of such a preamp in this circuit is desirable.
The following references are incorporated herein by reference in their entirety: Y. Tsividis, K. Suyama “Strange ways to use the MOSFET,” IEEE International Symposium on Circuits and Systems, pp. 449-452, June 1997; N. Krishnaswamy et al., “A Dual-Model 700-Msamples/s 6-bit 200-Msamples/s 7-bit A/D Converter in a 0.25-um Digital CMOST Process”; and S. Ranganathan, Y. Tsividis, “A MOS Capacitor-Based Discrete-Time Parametric Amplifier with 1.2 V Output Swing and 3 μW Power Dissipation,” IEEE International Solid-State Circuits Conference, Paper 23.1, 2003.